Evaporating apparatus.



A. REAVELL 61 W. G. MANAL.

EVAPORATING APPARATUS.

APPLICATION FILED NOV. 12. 1917.

Patented Apr. 23,1918.

JAMES ARTHUR REAVJELL AND WILFRED or. MANN, 01E LONDON, ENGLAND.

JEVAJE'ORATING IPAIUS.

Speciflcatiere Patent. I Patented Apr... 23, I9I@ Application filedNovember la, I917. flerial Ito. 201,673.

To all whom it may concern:

Be it known that we, JAMES ARTHUR REA- VELL and WILFRED GroncnMANN,subjects of the King of Great Britain and Ireland, both residing atLondon, England, have invented new and useful Improvements in andRelating to Evaporating Apparatus, of which the following is aspecification.

This invention has reference to improvements in and relating toevaporating apparatus (for use, inter can, in effecting-the desalting ofsaline solutions) of the type comprising a heater and a separator forseparating the vapor from the liquor through both of which theliquor-while being concentratedcirculates, the return flow of the liquorfrom the separator to the heater being through a conduit or pipeconnected to the separator at a point as nearas may be to the level ofthe liquid thereim I Owing to the return flow being thus from the upperpart of the body of liquor in the separator (which is as it should bewhen once the apparatus is in full operation because the upper part isleast concentrated) there is, when first starting, a large body ofliquor in the lower part of the separator which remains practically coldeven afterthe upper part is boiling, and this body of cold liquor canonly be heated by conduction, there being no convection currents.

As a consequence, even in the case of what I might be considered quitesmall apparatus,

it IS rarely possible to heat up the whole body of liquor to the desiredtemperature in less than four hours, and in the case of large apparatusit takes from 10 to 12 hoursfre-= quently much longer.

Further, the apparatus itself will be un-. equally heated and, owing tothe resultant unequal expansion, strains and stresses in the pipes andconnections generally are set up which-more especially in the case oflarge apparatus-fmrly, soon lead to leakac and at times even fracture,particularly i the apparatus has to be comparatively frequently closeddown, say for cleaning.

The object of our invention is to obviate this and to this end itconsists in providing the apparatus with an additional return flow .pipewhich is connected at one end as near as may be to the. bottom of theseparator and at its other end directly or indirectly to the beam.

mo construction of evaporation apparatus of the type referred to, havingour lnventlon applled to it, is illustrated more or lessdiagrammatically in sectional side elevation in the accompanyingdrawing.

In said drawing A designates the heater and B the separator. These areconnected in the known manner by pipes C and D having valves J and IIrespectively. The pipe 0 allows the liquor to flow from the heater tothe separator and the pipe D (which as is shown is connected to theseparator as high up as it conveniently can be) allows of the returnflow of the liquor from B to A when the apparatus is in full working.

Connected at one end as near as may be to the bottom of the separatorand at its other end to the return flow pipe D is a pipe E havin a valve15. It is by the installat1on of t is pipe, and its use as areturnflowwhen the apparatusis first started, that the defects referred to areobviated.

On first starting the apparatus-all the liquor being then coldsteam willbe admitted to the heater and the valve F at once opened. After a timethe liquor will begin to circulate, flowing from A through 0 into B andfrom B through E into A so that llquor at the bottom of the separator isat once withdrawn to be replaced by the warmer liquor above. After acomparatlvely short time the whole of the liquor will have been raisedto the desired temperature. When this is reached the valve F should beclosed so that thereafter the return flow from B to A will be throughthe valve II and pipe D. Y

Owin to the whole body of liquor having thus had its temperature raisedequally the apparatus will also be heated equally and I the stresses andstrains referred to obviated. en the valve F is open for the purposestated, the valve II may also be open either partly or completely, andinstead of connect- Iltll valve F opened for a short time to remove anysediment or the like at the bottom of the separator.

We wish it to be understood that while our invention is necessarilylimited in its application to an evaporator of the type described, we donot limit ourselves to the particular constructional form illustrated,as thisrepresentingas it does a form of such type of apparatus which isin use for desalting saline solutions and to which we have applied ourinvention-is given merely by way of example.

What we claim as our invention and desire alto" secure by Letters Patentis 1. In an evaporating apparatus, the combination of a heater, aseparator, pipes connected to the upper part of the separator andleading to the top and bottom respectively of the heater through whichpipes the circulation of the' liquor takes place when in full workingoperation, the heater being arranged substantially below the level ofthe'liquor in the separator whereby circula tion takes place from theheater through the upper pipe into the separator'and from the separatorthrough the lower pipe to the heater, and an additional .pipe leadingfrom the bottom of the separator to the lower part of the heatersubstantially as and for the purpose set forth.

2. In an evaporating apparatus, the combination of a heater, aseparator, pipes connected to the upper part of the separator andleading to the top and bottom respectively of the heater through whichpipes the circulation of the liquor takes place when in full workingoperation, the heater being arranged substantially below the level ofthe liquor in the separator whereby circulation takes place from theheater through the upper pipe into the separator and from the separatorthrough the lower pi e to the heater, and an additional pipe lea ingfrom the bottom of the separator, to the pipe connecting with the bottomof the heater and through said pipe to the lower art of the heater,substantially as and for t p purpose set forth.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

J. ARTHUR REAVELL. WILFRED G. MANN.

Witnesses Cms. BAUER, A. Caawmr.

